Geum Jan Di is from a poor family and is admitted to the prestigious Shinhwa High School after stopping a student who was being bullied from committing suicide. Shinhwa High was established by Shinhwa Group, the biggest conglomerate in Korea, and is attended by the scions of the wealthiest families. At Shinhwa, she finds that a group of rich and good-looking boys called "F4" ("Flower 4" or "Flamboyant 4") who enjoys tremendous popularity. The F4, however, thinks nothing of humiliating others, and often issues a "red card". Whoever finds the dreaded red card in his or her locker subsequently becomes the target of bullying by the entire student body. Jan Di detests all this circus, but receives a red card herself and is bullied, after she stands up for one of her fellow classmates. Eventually, she begins to have feelings for one of the F4, Ji-hoo, but also discovers that the leader of the group, Jun Pyo, is falling for her, too. A love triangle thus develops among Jun Pyo, Jan Di and Ji Hoo.